Protective Effects of Walnut Extract Against Amyloid Beta Peptide-Induced Cell Death and Oxidative Stress in PC12 Cells

Amyloid beta-protein (Aβ) is the major component of senile plaques and cerebrovascular amyloid deposits in individuals with Alzheimer’s disease. Aβ is known to increase free radical production in neuronal cells, leading to oxidative stress and cell death. Recently, considerable attention has been focused on dietary antioxidants that are able to scavenge reactive oxygen species (ROS), thereby offering protection against oxidative stress. Walnuts are rich in components that have anti-oxidant and anti-inflammatory properties. The inhibition of in vitro fibrillization of synthetic Aβ, and solubilization of preformed fibrillar Aβ by walnut extract was previously reported. The present study was designed to investigate whether walnut extract can protect against Aβ-induced oxidative damage and cytotoxicity. The effect of walnut extract on Aβ-induced cellular damage, ROS generation and apoptosis in PC12 pheochromocytoma cells was studied. Walnut extract reduced Aβ-mediated cell death assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) reduction, and release of lactate dehydrogenase (membrane damage), DNA damage (apoptosis) and generation of ROS in a concentration-dependent manner. These results suggest that walnut extract can counteract Aβ-induced oxidative stress and associated cell death

Reconnaissance de la parole et indices de segmentation métriques et phonotactiques

Summary: Cooperation and conflict between metrical cues and phonotactic cues in speech segmentation. Three experiments are reported concerning the relative contributions of metrical and phonotactic segmentation cues to listeners' word recognition in French. Listeners had to detect monosyllabic words embedded at the initial position in nonsense bisyllabic strings that were realized as an iambe, typical in French for bisyllabic words, a trochee, or a spondee. Experiment 1 extended the effect of metrical eues to the sequences with two non-coarticulated consonants in the medial position. Word detection was faster for a trochaic pattern than for either an iambic pattern or a neutral spondee. Comparing the effects of cooperating cues and of conflicting cues on detection times, Experiment 2 found neither interference nor interaction between the phonotactic and prosodie speech dimensions, but a redundancy gain in the trochaic condition for both phonotactic conditions. A control experiment studied the recognition of words extracted from the bisyllabic sequences. It showed no effect of previous context on word recognition. These results are discussed in terms of timing mechanisms that may operate either at the level of syllable perception, or as the basis of a prosodic parsing routine. They indicate that phonotactic and metrical cues are processed separately. Key words : speech perception, lexical parsing, speech segmentation, phonotactic cues, metrical eues.Résumé Trois expériences étudient les contributions relatives d'indices de segmentation métriques et phonotactiques à la reconnaissance des mots. La tâche consistait à détecter un mot monosyllabique situé au début d'une séquence bisyllabique sans signification, dont la structure métrique était celle d'un iambe (bref-long, structure usuelle des bisyllabes), d'un trochée (long-bref) ou d'un spondée (long-long). L'effet facilitateur du pattern trochaïque se produit même lorsque la structure phonotactique impose une segmentation, la consonne finale du mot ne pouvant être coarticulée avec le phonème suivant (expérience 1). Lorsque sont confrontés indices phonotactiques (discontinuité sylla-biquelliaison) et métriques (expérience 2), on constate à nouveau un gain en présence d'un trochée, mais pas d'interaction entre les deux dimensions étudiées. Quand les mots sont extraits des suites sans signification (expérience 3), leur contexte d'origine n'a pas d'effet sur leur reconnaissance. Les résultats sont discutés en référence aux mécanismes de traitement de la temporalité à l'œuvre dans la reconnaissance de la parole. On en conclut à un traitement séparé des informations structurales et prosodiques. Mots-clés : perception de la parole, segmentation lexicale, indices phonotactiques, indices métriques.Banel M.-H., Bacri N. Reconnaissance de la parole et indices de segmentation métriques et phonotactiques. In: L'année psychologique. 1997 vol. 97, n°1. pp. 77-112

Quantification of Aqueous Monoethanolamine Concentration by Gas Chromatography for Postcombustion Capture of CO 2

The availability of reliable analytical methods for measuring amine concentrations is necessary for optimum operation of aqueous amine CO 2 separation systems being employed for postcombustion capture (PCC) of CO2. A GC-FID (gas chromatography with flame ionization detection) method is described for the reliable quantification of 30% (w/w) monoethanolamine (MEA) in severely degraded solvent samples. The observation of intermittent splitting of the MEA peak was a major concern with this approach. The use of a wide-bore column led to improved MEA peak resolution and peak shape. The reliability and robustness of the GC-FID method were assessed by analyzing degraded 30% (w/w) MEA solvent samples from CSIRO's pilot plant at AGL's Loy Yang power station in Victoria, Australia. The results were compared with those obtained by titration and total organic carbon (TOC) measurements of the same samples. The MEA concentrations obtained by the GC-FID and titration methods were statistically similar. In contrast, the MEA concentrations calculated from TOC were consistently higher than those obtained by both GC-FID and titration. © 2014 American Chemical Society

An intonational cue to word segmentation in phonemically identical sequences

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